package org.stone.project.common.utils;

import java.io.UnsupportedEncodingException;
import java.nio.charset.StandardCharsets;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

/**
 * Md5加密方法
 */
public class Md5Utils
{
    private static byte[] md5(String s) throws UnsupportedEncodingException, NoSuchAlgorithmException {
        MessageDigest algorithm= MessageDigest.getInstance("MD5");
        algorithm.reset();
        algorithm.update(s.getBytes("UTF-8"));
        byte[] messageDigest = algorithm.digest();
        return messageDigest;
    }

    private static final String toHex(byte hash[])
    {
        if (hash == null)
        {
            return null;
        }
        StringBuffer buf = new StringBuffer(hash.length * 2);
        int i;

        for (i = 0; i < hash.length; i++)
        {
            if ((hash[i] & 0xff) < 0x10)
            {
                buf.append("0");
            }
            buf.append(Long.toString(hash[i] & 0xff, 16));
        }
        return buf.toString();
    }

    public static String hash(String s) throws UnsupportedEncodingException, NoSuchAlgorithmException {
        return new String(toHex(md5(s)).getBytes(StandardCharsets.UTF_8), StandardCharsets.UTF_8);
    }
}
